Premier League club Newcastle will take on Championship side Blackburn in the third round of the FA Cup this season.
The tie will be played at the Magpies' home ground St. James’ Park and will see Armstrong return to his former club to face Rafael Benitez’s side.
The 21-year-old striker came through the Newcastle academy and joined Blackburn on a permanent contract in the summer transfer window for a fee reported by Sky Sports to be worth £1.75 million.
The England Under-21 international could feature for Blackburn at St. James’ Park, and Newcastle have sent a message to the youngster on Twitter.
Armstrong has made 12 starts and six substitute appearances in the Championship for Blackburn so far this season, scoring one goal in the process, according to WhoScored.
Tony Mowbray’s side are 10th in the Championship table at the moment with 29 points from 20 matches, five points behind sixth-placed Sheffield United.
As for Newcastle, the Magpies are currently just three points above the Premier League relegation zone.